A process for the preparation of a carbamate-functional triazine has been known from U.S. Pat. No. 5,705,641. This process involves reacting an aminotriazine having at least two amino groups, with an acyclic organic carbonate, in the presence of a base. Useful bases are listed as “alkali metal hydrides, alkali metal alkoxides, alkali metal hydroxides, alkali metal oxides, alkali metal carbonates, quaternary ammonium alkoxides, quaternary ammonium hydroxides, quaternary phosphonium alkoxides, quaternary phosphonium hydroxides, tertiary amines and mixtures thereof. Sodium and potassium alkoxides are most preferred, and include linear, branched and cyclic alkyl group containing alkoxides and mixtures thereof”. While there is a general allusion to mixtures, the mandatory presence of bases from at least two different metals is not disclosed, and not exemplified in any of the examples.
It has been found in the experiments on which the present invention is based that excessively high viscosity occurs during the reaction which leads to excessive energy consumption for homogenisation during the reaction, and either the need to use special equipment such as thin film reactors or kneaders, or to the use or more diluted reaction mixtures with the consequent loss in space-time yield. It has therefore been desired to reduce the viscosity of the reaction mixture without having to resort to lower concentrations, or having to use special equipment. Reduced viscosity allows to increase the concentration of the desired product in the reaction mixture, thus also increasing space-time yield, and avoiding product losses.